{"id":"UBUNTU-CVE-2026-23831","details":"Rekor is a software supply chain transparency log. In versions 1.4.3 and below, the entry implementation can panic on attacker-controlled input when canonicalizing a proposed entry with an empty spec.message, causing nil Pointer Dereference. Function validate() returns nil (success) when message is empty, leaving sign1Msg uninitialized, and Canonicalize() later dereferences v.sign1Msg.Payload. A malformed proposed entry of the cose/v0.0.1 type can cause a panic on a thread within the Rekor process. The thread is recovered so the client receives a 500 error message and service still continues, so the availability impact of this is minimal. This issue has been fixed in version 1.5.0.","modified":"2026-07-02T18:02:37.203228141Z","published":"2026-01-22T22:16:00Z","upstream":["CVE-2026-23831"],"references":[{"type":"REPORT","url":"https://ubuntu.com/security/CVE-2026-23831"},{"type":"REPORT","url":"https://www.cve.org/CVERecord?id=CVE-2026-23831"},{"type":"REPORT","url":"https://github.com/sigstore/rekor/security/advisories/GHSA-273p-m2cw-6833"},{"type":"REPORT","url":"https://github.com/sigstore/rekor/commit/39bae3d192bce48ef4ef2cbd1788fb5770fee8cd"},{"type":"REPORT","url":"https://github.com/sigstore/rekor/releases/tag/v1.5.0"}],"affected":[{"package":{"name":"rekor","ecosystem":"Ubuntu:25.10","purl":"pkg:deb/ubuntu/rekor?arch=source&distro=questing"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["1.3.7-1","1.3.9-1"],"ecosystem_specific":{"binaries":[{"binary_name":"golang-github-sigstore-rekor-dev","binary_version":"1.3.9-1"},{"binary_version":"1.3.9-1","binary_name":"rekor"}]},"database_specific":{"source":"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-23831.json"}},{"package":{"name":"rekor","ecosystem":"Ubuntu:Pro:26.04:LTS","purl":"pkg:deb/ubuntu/rekor?arch=source&distro=esm-apps%2Fresolute"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["1.3.9-1","1.5.0-1","1.5.0-1ubuntu0.26.04.1~esm1"],"ecosystem_specific":{"binaries":[{"binary_version":"1.5.0-1ubuntu0.26.04.1~esm1","binary_name":"golang-github-sigstore-rekor-dev"},{"binary_name":"rekor","binary_version":"1.5.0-1ubuntu0.26.04.1~esm1"}]},"database_specific":{"source":"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-23831.json"}}],"schema_version":"1.7.5","severity":[{"type":"CVSS_V3","score":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L"},{"type":"Ubuntu","score":"medium"}]}